A simple Xhamster bot, which parses through pages and download the video's links, you can attach the url's into YTD (YouTube Downloader ). You have to edit a bit the code. The code works on Python 2.X, it won't work on Python 3.X.
The URLs will be saved into an exe file. Please use some "professional" IDE to run the code. I prefer WingIDE to run and edit my codes. If you have want to ask anythin about the code you can contact me below in the comment section.
The code requires Selenium to work.
To get any "niche" you must edit this line:
videos1 = FindVideo("http://xhamster.com/channels/new-big_natural_tits-",n)
You must copy the url as the same method : http://xhamster.com/channels/new-big_natural_tits- . So select a niche, copy it's URL and remove the number from the end.